Obesity and the risk of cardiovascular and all-cause mortality in chronic kidney disease: A systematic review and meta-analysis

Maleeka Ladhani, Jonathan C. Craig, Michelle Irving, Philip A. Clayton, Germaine Wong

Research output: Contribution to journalReview article

33 Citations (Scopus)

Abstract

Background: Obesity is a risk factor for cardiovascular disease and death in people without chronic kidney disease (CKD), but the effect of obesity in people with CKD is uncertain. Methods: Medline and Embase (from inception to January 2015) were searched for cohort studies measuring obesity by body mass index (BMI), waist:hip ratio (WHR) and/or waist circumference (WC) and all-cause and cardiovascular mortality or events in patients with any stage of CKD. Data were summarized using random effects models. Meta-regression was conducted to assess sources of heterogeneity. Results: Of 4065 potentially eligible citations, 165 studies (n = 1 534 845 participants) were analyzed. In studies that found a nonlinear relationship, underweight people with CKD (3-5) on hemodialysis experienced an increased risk of death compared with those with normal weight. In transplant recipients, excess risk was observed at levels of morbid obesity (>35 kg/m2). Of studies that found the relationship to be linear, a 1 kg/m2 increase in BMI was associated with a 3 and 4% reduction in all-cause and cardiovascular mortality in patients on hemodialysis, respectively {adjusted hazard ratio [HR] 0.97 [95% confidence interval (CI) 0.96-0.98] and adjusted HR 0.96 (95% CI 0.92-1.00)}. In CKD Stages 3-5, for every 1 kg/m2 increase in BMI there was a 1% reduction in all-cause mortality [HR 0.99 (95% CI 0.0.97-1.00)]. There was no apparent association between obesity and mortality in transplanted patients or those on peritoneal dialysis. Sparse data for WHR and WC did not allow further analyses. Conclusions: Being obese may be protective for all-cause mortality in the predialysis and hemodialysis populations, while being underweight suggests increased risk, but not in transplant recipients.

Original languageEnglish
Pages (from-to)439-449
Number of pages11
JournalNephrology Dialysis Transplantation
Volume32
Issue number3
DOIs
Publication statusPublished - 1 Mar 2017
Externally publishedYes

Keywords

  • cardiovascular mortality
  • chronic kidney disease
  • meta-analysis
  • mortality
  • obesity
  • systematic review

ASJC Scopus subject areas

  • Nephrology
  • Transplantation

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